Many electronic systems benefit from or require accurate timing synchronization between various components, which may be called “hosts” or “host devices.” Such systems may need to maintain this accurate timing synchronization over long periods of time. Examples of such systems include those using a phased antenna array, such as a radio-astronomy system or a phase-array radar system, in which a plurality of signals from a plurality of antennas or antenna elements must be accurately synchronized for proper aggregation and analysis.
Such a system may generate a master system clock that is distributed to each of the plurality of host devices to synchronize the devices with each other and with the system as a whole.
Host devices may be located remotely from the location of the master-system-clock generator, and the distance between a particular host device and the clock generator may vary among the host devices.
Disparate distances between the master-system-clock generator and the host devices may complicate timing synchronization among the host devices and between the host devices and other components of the system.
Furthermore, although the distance between a particular host device and the clock generator may be known and compensated for when a system is installed, events that occur in the system may introduce errors into the system synchronization. Examples of events that may introduce errors into the system synchronization include aging of system components, exposure of system components to radiation, changes in the temperatures of the system components, and electromagnetic interference (e.g., noise).
Although expected levels of such synchronization-degrading events may be determined and compensated for at the time of system installation, such synchronization compensation may become insufficient as the level of an event changes over time, or may be insufficient if an event occurs at a level that is outside of an expected range.